Alkenyl alkali metal compounds



Patented Nov. 16, 1948 2,454,082 ALKENYL ALKALI METAL coMroUNns Avery A. Morton, Watertown, Mass, assignor to Research Corporation, New York, N. Y., a corporation of New York No Drawing. Application October 17, 1945, Serial No. 622,941

6 Claims.

This invention relates to a method of producing alkenyl compounds particularly alkenyl alkali metals and alkenyl carboxylic acids.

It has been found that by the reaction of the readily obtained alkyl alkali metal compounds, such as alkyl sodium and alkyl potassium with olefinic hydrocarbons, the corresponding alkenyl alkali metal compounds are formed in good yield. The reaction is preferably carried out in the presence of an inert liquid medium, such as pentane or other liquid aliphatic hydrocarbons.

The alkenyl alkali metal compounds are readily converted into unsaturated carboxylic acids by treatment with carbon dioxide. This method makes possible the production of a wide variety of unsaturated acids, particularly the heretofore unavailable py-unsaturated carboxylic acids.

The invention will be more particularly described with reference to the following examples illustrating the principles of the invention.

1. Amylsodium (0.19 mol.) is prepared in the usual manner from amyl chloride and sodium sand in pentane. Isobutene (0.34 mol.) is then added dropwise over a half-hour period at 25 C. Stirring is continued for five hours and the isobutenyl-l-sodium reaction product is then carbonated by passing carbon dioxide into the mixture .for several hours. After carbonation, water is added, the aqueous layer is separated and acidified, and the acid is extracted with petroleum ether. On evaporation of the petroleum ether extract and cooling the pale yellow oil thus obtained to 0., colorless needles of [i-methyl vinylacetio acid are formed, melting at approximately 20 C. and having a refractive index 2. Amylpotassium is prepared by the addition over a one-hour period of gm. of amyl chloride, dissolved in 40 ml. of pentane, to 11 gm. of finely divided potassium metal suspended in 200 ml. of pentane at --10 to 15 C. ml. of l-pentene is added at -20 to the amylpotassium thus prepared. The temperature is then allowed to rise to and is maintained there for five hours.

The 1-pentenyl-3-potassium and l-p-entenyll-potassium thus formed are converted by carbonation into the corresponding hexenoic acids.

3. The alkenyl alkali metal compounds can 2 also conveniently be prepared by the reaction of an alkyl halide with an alkali metal in the presence of a liquid olefinic hydrocarbon. For example, 30.6 ml. of amyl chloride is added dropwise to a suspension of 11.6 gm. of fine sodium sand in 200 ml. of l-pentene ata temperature of 10 C. over a period of about an hour. The reaction mixture is then stirred for about three hours at 2025 C. A nearly quantitative yield of 1-pentenyl-3-sodium and l-pentenyl-l-sodium in the proportion of about 4 to 1 is produced.

4. By replacing the isobutene in Example 1, by propene, propenylsodium is produced which may be converted to vinylacetic acid by carbonation.

5. correspondingly alkenyl alkali metals and unsaturated carboxylic acids, may be obtained by substituting other olefins, such as l-butene, Z-butene, trimethylethylene and tetram'ethylethylene for the isobutene in Example 1.

Other alkyl alkali metals than the amyl compounds specifically referred to in the examples may also be used, for example, butylpotassium.

I claim:

1. The method of making alkenyl alkali metal compounds which comprises maintaining an alkali metal compound selected from the group consisting of alkyl sodium and alkyl potassium in intimate admixture with a mono-olefinic aliphatic hydrocarbon containing at least three carbon atoms.

2. The method of making alkenyl alkali metal compounds which comprises maintaining an alkali metal compound selected from the group consisting of alkyl sodium and alkyl potassium in intimate admixture with a mono-olefinic aliphatic hydrocarbon containing at least three carbon atoms in an inert liquid hydrocarbon.

3. The method of making isobutenyl alkali metal compounds which comprises maintaining an alkali metal compounds selected from the group consisting of alkyl sodium and alkyl potassium in intimate admixture with isobutene.

4. The method of making isobutenyl alkali metal compounds which comprises maintaining an alkali metal compound selected from the group consisting of alkyl sodium and alkyl potassium in intimate admixture with isobutene in an inert liquid aliphatic hydrocarbon.

5. The method of making l-pentenyl alkali metal compounds which comprises maintaining 3 an alkali metal compound selected from the group consisting of alkyl sodium and alkyl potassium in intimate admixture with l-pentene.

6. The method of making l-pentenyl alkali metal compounds which comprises admixing an alkyl halide with an alkali metal selected from the group consisting of sodium and potassium in the presence of l-pentene and agitating the resulting mixture.

AVERY A. MORTON.

Name Date Morton June 27', 1939 Number Number Name Date 2,171,868 Scott et a1 Sept. 5, 1939 2,352,461 Walker June 27, 1944 2,377,779 Hanford et a1 June 5, 1945 FOREIGN PATENTS Number Country Date 487,727 Germany Jan. 7, 1930 OTHER REFERENCES (Deutsche Chem. 

